Step 5: Burn!! Maw ha ha!!
You'll need to design three primary systems:
*fuel injector(s) \ nozzle(s)
Ignition can be as simple as a lighter or an electric igniter. It's as simple or complex as you want it to be. best option is an electric igniter probably.
fuel injectors or nozzles are important as they atomize the fuel into a fine mist ideally for optimum combustion. A simple pulse jet has but one nozzle while aircraft engines can have 16 in a ring like formation. The nozzle should face away from the direction of air flow and is placed at the front of the chamber (the front being where the air comes in (unless a pulse jet). You'll also need to figure out how your fuel is going to be forced through the nozzle. You could have a pump or have a pressurized container like a propane tank (which is common for pulse jets).
Okay, now for the burner can. You might know this as a flame holder or some such. Without it, your combustion section would likely melt or deform under the intense heat. It's a can like structure that directs the flame onto your turbine. I should mention pulse jets don't need them (which is why they glow sizzling red hot). The fuel nozzle is aimed into the front of the burner can (front being what the air enters from). Your igniter will also need to enter the can to start combustion. The burner can has many small holes drilled along its entire surface. This allows air from your compressor to enter the inside of the burner can and focus the flame's path. The hot expanding gases from the burner can are then directed aft onto the turbine. For a better understanding, look closely at the configuration(s) in the pics. Oh and it will need to be made of a metal that can hold up under high temps.